<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>百度按钮</title>
  <style>
    input,div,span,a {
      width: 150px;
      height: 50px;
      color:#fff;
      font-size: 20px;
      font-family: 黑体;
      background-color: #4662D9;/* 背景颜色 */
    }

     input:hover,div:hover,span:hover{
      background-color: #3f57c5;
    }

    input{
      border:0;/* 边框 */
      cursor: pointer;/* 鼠标指针样式 */
    }

    a{
      display: block;/* 转换块级元素 */
      text-decoration: none;
      text-align: center;
      line-height: 50px;
    }

    div{
      text-align: center;
      line-height: 50px;
      cursor: pointer;/* 鼠标指针样式 */
    }

    span{
      display: block;/* 转换块级元素 */
      text-align: center;
      line-height: 50px;
      cursor: pointer;/* 鼠标指针样式 */
    }
  </style>
</head>
<body>
  <!-- button -->
  <input type="button" value="百度一下"/>

  <hr/>

  <!-- a -->
  <a href="#">百度一下</a>

  <hr/>

  <!-- div -->
  <div>百度一下</div>

  <hr>

  <!-- span -->
  <span>百度一下</span>
</body>
</html>